The last time I thought about taking heroin was yesterday. I had received "an inconvenient truth" from a beautiful woman. It wasn't about climate change - I'm not that ecologically switched on, she told me she was pregnant and it wasn't mine.

[Sidebar: Does this mean his ex-wife Katy Perry is pregnant with boyfriend John Mayer's baby?]

After hearing the news, Brand got in his car and turned on Morrissey as he wound his way through the Hollywood Hills. But a car ride wasn't easing his pain the way heroin used to, he says.

I cannot accurately convey to you the efficiency of heroin in neutralizing pain. It transforms a tight, white fist into a gentle, brown wave. From my first inhalation fifteen years ago it fumigated my private hell and lay me down in it's hazy pastures and a bathroom floor in Hackney embraced me like a womb.

This shadow is darkly cast on the retina of my soul and whenever I am dislodged from comfort my focus falls there.

Brand, now sober, then explains that he recently saw video footage of himself as a young drug addict living in London.

I sit wasted and slumped with an unacceptable haircut against a wall in another Hackney flat (Hackney is starting to seem like part of the problem) inhaling fizzy, black snakes of smack off a scrap of crumpled foil.

But his present-day reaction wasn't what he thought it would be.

... What is surprising is that my reaction is not one of gratitude for the positive changes I've experienced but envy at witnessing an earlier version of myself unencumbered by the burden of abstinence.

It is thanks to support groups that Brand says he is able to remain sober.

Without these fellowships I would take drugs. Because, even now, the condition persists. Drugs and alcohol are not my problem, reality is my problem, drugs and alcohol are my solution.

... I look to drugs and booze to fill up a hole in me, unchecked the call of the wild is too strong.

Brand, still feeling lonely and sad after the news of a lost love now moving on, waxes poetic about what it would be like — and how easy it would be — to go back to using to ease his pain.

I think of places I could score. Off Santa Monica there's a homeless man who I know uses gear. I could find him, buy him a bag if he takes me to score.

I'd leave him on the corner, a couple of rocks, a couple of $20 bags pressed into my sweaty palm. I get home, I pull out the foil, neatly torn. I break the bottom off a Martel miniature. I have cigarettes, using makes me need fags. I make a pipe for the rocks with the bottle. I lay a strip of foil on the counter to chase the brown. I pause to reflect and regret that I don't know how to fix, only smoke, feeling inferior even in the manner of my using. I see the foil scorch. I hear the crackle from which crack gets it's name. I feel the plastic fog hit the back of my yawning throat. Eyes up. Back relaxing, the bottle drops and the greedy bliss eats my pain. There is no girl, there is no tomorrow, there is nothing but the bilious kiss of the greedy bliss.

But once again, it's a "mate" in London, a former user, who picks up Brand's phone call and keeps him on his path of sobriety.

It is ten years since I used drugs or drank alcohol and my life has immeasurably improved. I have a job, a house, a cat, good friendships and generally a bright outlook.

To read Russell's moving blog post in its entirety and learn more about his "Give It Up" fund within Comic Relief, click here >